The field of the present invention is apparatus for heating water for beverages, such as coffee and tea, and particularly for use in passenger service systems in commercial airline planes.
Commercial airlines have attempted to make air travel a comfortable and pleasant experience. To that end, airlines have provided in-flight beverage services to their passengers, but providing hot beverages such as coffee and tea to airplane passengers has not proven to be a simple task. The quality of the available water is not consistent in all airports and often contains high concentrations of minerals that become deposited in the water heating tank. As a result some airlines have required cleaning the heating tank used to produce the hot water for hot beverages as often as once a month. Considering the present construction of heating tanks, cleaning the inside of the tank and the tank's heaters is a long and labor intensive task requiring the removal of as many as five separate fastening devices on the top of the heating tank alone. Further, using five separate connectors to assemble the heating tank increases the likelihood of leaking and improper reassembly.
More importantly, heating water in an enclosed tank can create dangerously high pressures possibly resulting in explosions. For this reason, pressure release valves have been integrated into heating tank designs to reduce the frequency and severity of such catastrophes. However, the pressure release valve is typically sealed within the tank or some integral component thereof, and if the valve can be serviced at all it is only by disassembly of the heating tank. Thus, the chance that the servicing of the pressure release safety valves might be delayed or omitted resulting in the malfunction of a safety release valve is increased.
Finally, because of the weight and space concerns inherent in air travel, the airlines are constantly searching for elements that may be combined or even eliminated.